Later he was freed and moved to the United Kingdom, spending a short time with the Polish aircraft division. In 1944-5, he continued his medical studies in Edinburgh, graduating in 1946. Soon he returned to Poland and took up psychiatry at the Psychiatric Clinic in Collegium Medicum of the Jagiellonian University in Kraków. Shortly before his death in 1972 he was appointed as Professor of that Faculty.[3]

As a concentration camp inmate himself, Kępiński took part in a rehabilitation programme for survivors from the Auschwitz concentration camp.[2]

Information metabolism is a psychological theory of interaction between biological organisms and their environment based on information processing.[4] The most detailed description of information metabolism concept is given in his book "Melancholy".[5] In this model, the living organism is considered an open system as understood by von Bertalanffy. Living beings are characterized by ability to increase and maintain their own negentropy. This ability makes the difference between them and inanimate objects which obey the increase of entropy principle. The body retains the same basic structure, although its building elements (molecules) are replaced quite frequently in anabolic and catabolic processes. The energy derived from food and oxygen is spent on securing the integrity of the organism. To refer to anabolic and catabolic processes in cells Kępiński used the term "energy metabolism". Any activity of an organism is an informational sign to other beings. Activities in the physical realm are reactions to changes perceived in the external or internal reality of the organism. Bearing that in mind, the psyche can be seen as the information-processing unit. As emhpasized by Kępiński, psychological structure of an individual remains relatively stable despite an ongoing exchange of information, analogically to the physical structure subject to energy metabolism.[6] In his books, Kępiński explained various mental conditions as disorders and imbalances of the information metabolism.

Bielecki, A. (2000) A mathematical model of Kepinski's information metabolism model theory. Proceedings of the Sixth National Conference on Application of Mathematics in Biology and Medicine, Zawoja, 9-13.